Topeka ? An Army general has reduced the prison sentence of a Fort Riley soldier convicted in the alleged mercy-killing of a severely injured Iraqi teenager in 2004.

Staff Sgt. Johnny Horne Jr., 31, of Wilson, N.C., is set for release in September from the Fort Lewis Regional Correctional Facility in Washington.

He pleaded guilty at a December court martial, but his three-year prison sentence for the unpremeditated murder of the Iraqi was reduced in June by Maj. Gen. Peter Chiarelli, commander of the 1st Cavalry Division at Fort Hood, Texas.

Master Sgt. David Larsen, a spokesman for the division, said Chiarelli didn’t indicate why he was reducing Horne’s prison term.

“He considered the record of trial, information provided by the defense and the staff judge advocate’s advice on sentencing,” Larsen said.

However, Larsen declined to comment on allegations made by a group of veterans from West Virginia who claim Horne was wrongly prosecuted and are seeking to clear his name.

Horne was deployed to Iraq in June 2004 for a yearlong tour, the second for his regiment in two years. Horne’s platoon was patrolling Sadr City outside Baghdad when troops spotted a dump truck carrying civilians who were throwing explosives from it. After soldiers fired on the truck, Horne’s group was ordered to investigate.

What it found were several dead Iraqis and a man who was badly burned hanging from the truck’s cab. Horne handed him to a medic and turned his attention to a dying teenager with severe abdominal wounds.

Horne said he moved the boy from the truck and left him, but was later ordered to shoot him. Another soldier shot the boy, but Horne said he was still breathing. That’s when Horne shot the boy in the head. A criminal investigator later said that the U.S. soldiers had decided that “the best course of action was to put (the victim) out of his misery.”

The lieutenant has denied giving the order and Horne was charged with premeditated murder, conspiracy and soliciting another soldier to commit murder. A second Fort Riley soldier, Staff Sgt. Cardenas J. Alban of Inglewood, Calif., was sentenced to one year in prison for murder for the same incident.

However, a group of veterans from Madison, W.Va., are convinced Horne shouldn’t have been charged or convicted and are fighting on Horne’s behalf.